Dental impression reenforcement tray



Aug. 20, 1935. L. KALVIN DENTAL IMPRESSION REENFQRCEMENT TRAYS Filed Oct 18; 1952 3 Sheets-Sheet l INVENTOR Louis Elli/Zn Aug. 20, 1935. L. KALVIN 2,011,860

DENTAL IMPRESSION REENFORCEMENT TRAYS Filed Oct. 18, 1952 5 Sheets$heet 2 INVENTOR Louis Kale/in KTT EY3 Aug. 20, 1935. L. KALVIN DENTAL IMPRESSION REFENFORCEMENT TRAYS Filed Oct 18, 1932 3 Sheets-Sheet 3 INVENTOR Louzls' [fall/m "PatentedAu g. 29,1935 v o 2,0llt860 PUNITED STAT-ES PATENT OFFICE Louis Kalvin, New York, N. Y. v t I Application October 1s 1932, Serial No. 638,310' t 10 Claims. (01. 32-1 This. invention relates to trays for bonding open-worker mesh material, through the spaces and .reenforcing dental impressions-which are to of which the fluid or plastic impressionmaterial be made in plastenmodeling compound; or other can flow, and with which'the impression material plastic material. I 1 becomes adherent when set, so that a firm key- 5 The present-application is a continuation in ing of the latter to the bonding tray occurs. To '5 part of my prior application, Serial No; 551,869, facilitate the separation of the impression into filed July 20, 1931. i e r 7 a predetermined number of pieces on definite and An important object of the invention is to 1m certain parting lines, the bonding and reenforce- .prove the practice withregardto making dental ment tray may be provided with parting partir 10 impressions so as'to render the results more de- 'tion d s Which p t t the Pouring Spa 0 pendable. and are backed with an impervious backing so In the ordinary'process of making dental im that the resulting "impression is weakened on pressions of, for example, plaster of Paris, the these lines. Such impervious backing may be plaster is mixed with 'water, then poured into a 7 P d y the temporary pp r metal y,

supporting tray of metal or other suitable maor by an Outer p y 0f c se WOVen fabric, e

terial; the tray containing the plaster being inp a i y p rma y Secured 0 e p 'serted into the patients mouth and. pressed mesh reenforeemeht y- In One O t D againstfthe teeth and gums while the lesteris vterrecl forms f theiinvention, the p sh still wet and fluid, then held jin'place under y s in sections r s e n r eist i e w th suitable pressure while the partial setting of the each Other along these P t Dartitien lines 20 plaster occurs, whereupon the 'supporting trayf Q d e Such Segmen s being D p y 1 is freed by tappingor the like from the partially tioned in an outer ayer o perv us, c osely setplaster andthe plaster left in place until it w v n a t wh th se s ar n has completely set, V i mally firmly adherent on the contacting lines t The impression is' then broken into several their corrugations. but Which become a- 25 pieces along uncertain and irregular li so as ble therefrom under the influence of moisture or to admit of its removal. The making of the imat p s t i e plaster u n the p ocess pression is frequently the cause of great discomof setting, 50 that the impervious Outer layer fort'to the patient, "and the result is often a may be p d m therreenfotcementsegfailure, so that the entire operation has to be s w he ss 'h et' u 30 repeated. It'is not uncommon for three or four enable the impression to be broken along the failures-to occur beforea satisfactory 'impres definite Parting partition lines ridges Withsion is finally obt i dout the necessity ofsevering the reenforcement 1 One of the principal causes for failure in the t y. p i ordinary practice i th breaking of'thejmpfes- 7 Several embodiments of the invention are il- 3 sion into so many pieces, or the crumbling of the lustrated by way'of example in the. accompanying edges of the pieces to such an extent as to predrawings inylwhiche l .elude'the making of a good ca t from t Figure l is a perspective view of .a"reenforcepression. i y t ment tray comprising a single layer of corrugated, 40 In accordance with my invention I ensure the openemesh material- I 1 parting of the impre'ssionon predeterminedvpart- Figure 2 is. a perspectiveview of metal S ing lines so as; to always separate the impression ting tray which may be usedas a a i for into a definite numberof pieces, each piecebethe reehfercement tray: Shown in Figure ing reenforced 0r bonded to avoid crumbling or F gure 3 is a cross-sectionhf he injury. At the sametime, the bonding'and remerit. tray and supporting trayiiishown in Figures 45 enforcing tray, in accordance with my invention, Ii-94nd 2 respectivelyfacilitates the removal of the "metal supporting 1 Figure is s w, ii/1thv the'impression tray when the plaster has partially set. ater l p ace at the time otm n h ima In principle, the bonding and reenforcement ss i V tray of my present invention comprises a body Figure s a longitudinal Section O t Same;

formed with floor and flange members'to more "Figure 6 is a horizontal-fragmentary section or less closely fit the proper size of supporting of the same. a tray and to provide a pouring space for the im- Figure '7 is'a perspective view of a singlelayer .pression material. The bonding and reenforcereenforcement tray formed in separate sections or ment tray is'made preferably of stifl corrugated, "segments.

Figure 8 is a perspective View of a metal supporting tray for the reenforce'ment tray, shown in Figure '7'. V

Figure 9 is a longitudinal section of a segmentary reenforcement tray with an impervious backing layer, shown in a metal supporting tray during the taking of an impression.

Figure 10 is a horizontal fragmentary section'of thesame. I i I v t Figure 11 isia' perspective view of a one-piece reenforceme'nt tray provided with a one-piece impervious backing.

Figure 12 is a horizontal fragmentary section of the same with the impressiontherein.

Figure 13 isa perspective view of a segmentary' reenforcement tray, each segment of which is provided with an impervious backing layer.

Figure 14 is a perspective view u rith'pa-rts in section, of a formed impression having the reeniorcement tray embedded therein, with an "outer impervious backing layergsuch as shown in Fig- -ures 9 to 12' inclusive, being removed, and one of the s'egmentsof .the' impression or cast having been parted. I i

V Figure i5 is a-perspective views of a segmentaryreeniorcement tray for use in making'lower-impressions. s r

, Figure 16 is a perspective viewof a one-piece r'eenforce'ment tray of uncorrugated material pro- .vided withfa'peripheral'fiang'eto space it from its supporting trayiniuse.

Figure 17 is a cross-sectionof the: same as positioned in a supporting tray'. Figure 18 is a fragmentary horizontal section through an impression employing a tray of the type shown in Figures 16". andv 1'7.

Figure 19 is'a perspective view of a segmentary reenforcement tray of uncorrugate'd material pro-i Vided with peripheral flanges .to space-the segments from the. supportingtray; V Figure 20 is a cross-section of the parts shown in Figure 19, as positioned in the supporting tray.

In Figure 1 the reenforcement tray is illus- ,trated as comprising a single piece of open mesh fabric such as stiif and rather heavy buckram.- This materialmay .be moistened and. pressed into shape in hot dies ofsuitable configuration so as to provide a floor portion Lwith a flange 2 ex;

tending around the sides andiron't, with ahorizontal parting partition ridge 3 following the line of intersection betweenythe flange and floor portions and with two vertical parting partition ridges 4, 5: between thefront and side walls or flanges.

This reeniorcernent is "rather deeply corrugated so that when placed in, a supporting tray such, as

illustrated in Figure 2,-fit will provide flow spaces between the inner corrugations and the supporting tray in order that the plaster or thelikemay almost completely enclose thereenforcement prior to setting. The supporting tray illustrated in Figure 2 comprises a floor portion 6 with side flanges l, 8 and front flange 9 with a horizontal parting partition ridge [0 extending around the 1 "mesh on these lines.

line of intersection between the side and front flanges and the floor portion, and vertical parting partition ridges ll, I2 between the front flange and the respectiveside flanges l and 8. The side flanges l and 8 have rear. walls [3 and I l, which,

merge into the rear arch of the floor portion 6. A handle portion 6 is usually formed on the front of the supporting tray. V I

The parting partitionridg es, 3, 4. and 5 of the reenforcement tray register with the parting partition ridges I'U, II and I2 of the supporting tr and are preferably formed to. make substantially continuous contact therewith so as to prevent or limit the; flow of plaster through the Figure 3 illustrates the position ofthe reenforcement tray in the supporting tray prior to pouring the plaster, and'Flgure 4 illustratesthesame after the plaster has been poured and the impression made. In Figure, 4

it will be'observed that the plaster I5 has passed iAfter the plaster-has. partially set, the supporting tray is removed, leaving the plaster with its embedded reenforcement in place;after which the reenforcement tray, may be severed with a knife or other suitable implement along the lines of; the parting partition ridges and the reenforced impression or. cast then broken along will containitsreenforcement:

1 In Figures 7 and 8 thesame principle of construction is illustrated, with the exception; that in this example thereenfo'rcement tray is formed into. previously separatedsegments cemprising-the floor segment 15,-, side segments. i1 and 18,,and the front segmentxte. Each of these segments has ,its, respective peripheral flange or lip 26, 2 or 2-2, which follows the parting these, lines into definite segments, each of which 'partitionjridge-of the supporting, tray. These segments are placed in the supporting. tray, .as illustrated in Figure 8, bemgspo-tted thereto by wax or the like 2.3. The; construction illustrated permits the removal oithe supporting tray after the plaster has partially set, and eliminates the necessity oiesevering reeniorcement tray along the-parting partition ridges prior to the breaking of the cast into segments.

Figures 9 and 10 illustrate the embodiment of 'a segmentary reenforcement tray in' an impervious backing tray of fabric, the latter being in one piece, Here the reenforcem-enttray 24 in segments is temporarily secured in the impervious backing tray 25 or suitably. sized close mesh fabric. The sizing of the backing trayor layer 25 serves as 'an' adhesive for securing the 're'enforcement segments in place by the heat and pressure of the 'forming operation during the manufacture of the tray. The dampness and temperature of the setting plaster soften this adhesion so that "after removal of the outer supporting tray this backing layer- 25' maybe stripped fr'om the cast preparatory to the breaking of the latter along the parting partition lines. This operation is illustrated 'in' Figure 14 of the drawings, inwhicli the backing; layer 25 is partly removed and one of the'side segments 24* of theeast, is shown'bro-ken out from the main body 24%. ure'fllO shows a detailof the formed cast prior to'the removal of,.the, outer supporting tray 25 and the backing layer.- 25. It will be observed f rom jFigur'es Q'and ,lll thatthe segrnentary re,-

(til

enforcement tray 24 follows in construction the principles already'illustrated-in Figure 7.

Figures 11 and l2illustrate a construction in which a one-piece reenforcement tray 21, similar to that shown in Figure 1, is mounted in a onepiece backing layer 28, similar to that shown in Figures 9 and 10, the construction being such that the two layers may both be severed simultaneously along the partingpartition ridges prior to the breaking of the cast into'definite segments, or the backing layer-may be stripped from the cast prior to the separation of thepcast'intosegments. 1 Figure 13 illustrates a segmentary tray; each segment comprising an inner pervious reenforcement 29, and an outer impervious backing layer 39. These segments, being initially distinct, are assembled in a supportingtray, as already described,- forexample, in connection with Figures 7 and 8, sothat the finished cast may be'broken apart without the necessity of preliminarily stripping or severing the backing or severing the reenforcement. 1 V 1 r I Figure 15 illustrates the construction'described in connection with Figures 7 and 8,-as appliedin this instance to the lower impression. The number of segments in the case of an upper is usually four, whereas in the case of a lower the segments are usually six in number. The construction illustrated in Figure 15 thus comprises two outer segments 3|, 32 'for the sides, two inner segments 33, 34 for the} sides, one outersegment 35 for the front, and one inner segment 35 for the front. .This difference in' the number of segments in upper andlower impressions may be regarded as generally inherent to all of the constructions illustrated. e

The embodiments of the invention thus far described have illustrated the use of corrugations extending more or less-over the entire area of the reenfo-rcerne'nt tray, for the purposeof spacing it fromthe impervious outer surface,- whether such 'outer surface be the wall of a'metallic support ing tray or an impervious backing layer of close ly woven sizedfabric; The principles illustrated, however, are in large measure applicable in other respects to non-corrugated material,

In Figures 16, 1'7 and 18, for example, a onepiece open mesh fabric reenforcement 31, in noncorrugated form, is illustrated, this'having an out-turned peripheral flangetfl along theupper edge, interrupted at 39, 40,-to engage the sides and front of a supporting tray M to space the reenforcement layer from the supporting tray and thus provide flowing space for the plaster. The supporting tray 4i 'may have the horizontal and vertical parting partition ridges 42 and 43 against which thereenforcementtray rests. Such parting partition ridges thus cooperate with the out-turned edges 38 of the reenforcement, in spacing the latter'from'the supporting tray.

The interruptions 3Q, 40, in the peripheral outturned edge of the reenforcement, engage the vertical parting partition ridges 43 of the supporting tray, to= hold the reenforcement tray in place. Such interruptions may be produced either at the time of manufacture, or they may be formed by cutting out notches at the proper points at the time the reenforcement is fitted into the supporting tray.

Figures 19 and 20 illustrate the spacing of a segmentary reenforcement in much the same manner as that illustrated in Figures 16, 17 and 18, in connection with a single reenforcement tray. Each segment in this instance comprises a 'body portion 44 with out-turned edges 45, so thatthey may be properlyfitted into an impervious supporting, tray 46 which isprovided with a horizontal parting partition ridge 4? and vertical-parting partition ridges 48, the latter tic material such as partly vulcanized gunrrubher; This fin 49, out in proper width from a ,strip, hasa-triangular or wedge-shaped base 5fl,

conforming with the angle on the under surface of the parting partition ridge of the reenforcemerit, so that it may. be inserted upwardly through slit formed in the reenforcement tray at the proper point, and be held in vertical position by the engagement of itsibase with the under surface 0f the parting partition ridge, as clearly shown in Figure 22 By pulling this fin upwardly into its seat, the elasticity of the fin material allows itto stretch under thetension, and when the tension is released, the return tonormal thickness will result in its being firmly held by the pinch of the slitted reenforcement of backing layer. a The construction illustrated isapplicablemore particularly where a supporting tray 5i, without the horizontal parting partition ridge, is employed, and in such case the flat under surface of the base 58 of the parting fin engaging the fiat surface of h t the supporting tray further steadies the parting fin in its vertical position. 'I'his'parting fin is furthermore applicable whether the reenforcement tray is in one piece and has to; be slit for its reception, oris in segmentary form so that it does not require slitting'at the point where the fin is to be applied. It is also applicable to constructions in which the rcenforcement tray in one piece, or in several segments, is disposed in a temporary' or permanent backing layer in one piece or several segments, as illustrated in Figures-9 tol l inclusive. With whatever form of reenforcement or backing tray it is employed, it serves to provide a partition extending across the gap of parting. Being made of elastic material, it I may be withdrawn by taking hold of it'at .the'base by t reezers or other suitable implement, the elasticity enabling its thickness to'decrease asit is stretched, so that it may be very readily withdrawn afterthe' plaster has partly set, or even fully set, and the supporting tray has been removed. i

I have mentioned the use of sizing as a means of temporarily securing a reenforcement tray in one piece or several segments in animpervious outer layer'or'backing. The-ordinary sizing em ployed in buckram, in which starch, tapioca, glue,

dextrine and the like are employed, satisfactorily fulfills this purpose, as it holds well on being hot pressed to a dry state, and softens Well during the setting of the wet plaster. Plaster of Paris,

outer layer or backing. It is very desirable, on

the other hand, that the plaster adhere perma .nently with the reeniorcement mesh, and {or this reason I prefer to employ a sizing or dip for the reenforcement mesh which is not affected in this way by the heat and moisture present in the-set-,

ting of the plaster. ,An example of a suitable dip or sizing tdanswer these requirements is as follows:-- i

Seven pounds of gum varabic are thoroughly mixed with seven gallons of water, and'the mixture is allowed to stand overnight. One ounce of sodium benzoate dissolved in one'gallon of Warm Water, and five ounces of aluminum sulphate added th reto and thoroughly dissolved. A portion of the gum arabic solution (about one pailful) is then mixed thoroughlywith the solution of sodium benzoate and aluminum sulphate, after which the mixture is poured into the remainder of the gum arahic solution and thorough- 1y mixed. One pound of starch is mixed with one 'gallcnof water, and afterward boiled to a thick, starchy paste. 'I'his'paste is then added to the mixed solution containing the gum arabic,

aluminum sulphate and sodium benzoate, and

after thorough mixing, the resulting solution is strained through damp cheesecloth and is'ready for use.

. The iabric of which the reenforcement trays are to be made, is first'moistened or rinsed'in water, and then thoroughly soaked in the dip, prepared as described above; This treatment provides, at the sametime, for the stiffening or sizing'cfthe fabric. I 1 v Othertreatments, giving the same or substantially equivalent properties to the fabric, may ob viously be employed, instead of the one particu-.

or permanently applied to or in contact with the projections of the. reenforcement tray.

The resulting dental impression is in itself a new and useful article by reason of the incorporation of reenforcingmaterial directly in contact with, or actually within, the solidified plaster.

I claim:- s

1'.- A reenforcement tray for dental impressions comprising an open mesh fabric for use in conjunction with an impervious backing layer, and provided with means for maintaining flow spacesbetween themesh and the backing layer.

2; A reenforcernent tray for dental impressions comprising stiffened open mesh fabric and a backing layer impervious to liquid plaster,

. sions comprising. a plurality of separate, segments of open-work'material, and a backing layer associated therewith to, position the segments with respect to each other and limit the flow of plaster therethrough. J I

5. ,A reenforcement tray for dental impressions comprising an open-work reenforcement material adherent to setting plastenand a backing layer, said reenforcementmaterial and said backinglayer being secured together by material rendered'non adherent by the setting of the plaster.

06; A reenforcement tray fordental impressions comprising a plurality of segments of openwork reenforcement adherent to setting plaster,

and a backing layer positioning, said segments with respect-to each other and normally adherent thereto, but readily separable therefrom during the setting-of the plaster. r

7. A bonding reenforcement tray for denta impressions comprising superimposed inner and outer layers-0i sheet material, said inner layer being exposed directly to the plasticimpres'sion material and recessed to be pervious thereto and said outer layer-beingv substantially impervious to theplastic impression material, the two layers beingunited and formed with floor and flange portions to constitute a pouringspace for the impression material.

8. A device for use in the makingof dental impressions comprising in combination, a bonding .reenforcement trayhaving a pouring space for the impression material, with a parting partition ridge projecting thereinto, and a parting fin of elastic gum adapted to be inserted through said'ridge to'project into the pouring space beyond said ridge. I

9..A device for use in the making of dental impressions comprising in combination, a bonding reenforcement tray having a pouring space for the impression material, with a parting partition ridge projecting thereinto, and a parting finadapted to be passed inwardly, through the apex of said ridge, and having a base portion conforming with the outer angle of said ridge to steady the fin. i

10. A device for use in the making of dental impressions comprising in combination, a tray for -the.,impression material, and a parting fin of elastic gum having av Web portion adapted to be inserted, into the pouring space through a slit in said tray, and ahead portion adapted to abut against the outer surface of said tray.

' LOUIS KALVIN. 

